text-utils/rev.c

   1 /*-
   2  * Copyright (c) 1987, 1992 The Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * Modified for Linux by Charles Hannum (mycroft@gnu.ai.mit.edu)
  34  *                   and Brian Koehmstedt (bpk@gnu.ai.mit.edu)
  35  *
  36  * Wed Sep 14 22:26:00 1994: Patch from bjdouma <bjdouma@xs4all.nl> to handle
  37  *                           last line that has no newline correctly.
  38  * 3-Jun-1998: Patched by Nicolai Langfeldt to work better on Linux:
  39  *      Handle any-length-lines.  Code copied from util-linux' setpwnam.c
  40  * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
  41  *      added Native Language Support
  42  * 1999-09-19 Bruno Haible <haible@clisp.cons.org>
  43  *      modified to work correctly in multi-byte locales
  44  * July 2010 - Davidlohr Bueso <dave@gnu.org>
  45  *      Fixed memory leaks (including Linux signal handling)
  46  *      Added some memory allocation error handling
  47  *      Lowered the default buffer size to 256, instead of 512 bytes
  48  *      Changed tab indentation to 8 chars for better reading the code
  49  */
  50
  51 #include <stdarg.h>
  52 #include <sys/types.h>
  53 #include <errno.h>
  54 #include <stdio.h>
  55 #include <stdlib.h>
  56 #include <string.h>
  57 #include <unistd.h>
  58 #include <signal.h>
  59 #include <getopt.h>
  60
  61 #include "nls.h"
  62 #include "xalloc.h"
  63 #include "widechar.h"
  64 #include "c.h"
  65 #include "closestream.h"
  66
  67 wchar_t *buf;
  68
  69 static void sig_handler(int signo __attribute__ ((__unused__)))
  70 {
  71         free(buf);
  72         _exit(EXIT_SUCCESS);
  73 }
  74
  75 static void __attribute__ ((__noreturn__)) usage(FILE * out)
  76 {
  77         fprintf(out, _("Usage: %s [options] [file ...]\n"),
  78                 program_invocation_short_name);
  79
  80         fprintf(out, _("\nOptions:\n"
  81                        " -V, --version   output version information and exit\n"
  82                        " -h, --help      display this help and exit\n"));
  83
  84         fprintf(out, _("\nFor more information see rev(1).\n"));
  85
  86         exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
  87 }
  88
  89 static void reverse_str(wchar_t *str, size_t n)
  90 {
  91         size_t i;
  92
  93         for (i = 0; i < n / 2; ++i) {
  94                 wchar_t tmp = str[i];
  95                 str[i] = str[n - 1 - i];
  96                 str[n - 1 - i] = tmp;
  97         }
  98 }
  99
 100 int main(int argc, char *argv[])
 101 {
 102         char *filename = "stdin";
 103         size_t len, bufsiz = BUFSIZ;
 104         FILE *fp = stdin;
 105         int ch, rval = EXIT_SUCCESS;
 106
 107         static const struct option longopts[] = {
 108                 { "version",    no_argument,       0, 'V' },
 109                 { "help",       no_argument,       0, 'h' },
 110                 { NULL,         0, 0, 0 }
 111         };
 112
 113         setlocale(LC_ALL, "");
 114         bindtextdomain(PACKAGE, LOCALEDIR);
 115         textdomain(PACKAGE);
 116         atexit(close_stdout);
 117
 118         signal(SIGINT, sig_handler);
 119         signal(SIGTERM, sig_handler);
 120
 121         while ((ch = getopt_long(argc, argv, "Vh", longopts, NULL)) != -1)
 122                 switch(ch) {
 123                 case 'V':
 124                         printf(UTIL_LINUX_VERSION);
 125                         exit(EXIT_SUCCESS);
 126                 case 'h':
 127                         usage(stdout);
 128                 default:
 129                         usage(stderr);
 130                 }
 131
 132         argc -= optind;
 133         argv += optind;
 134
 135         buf = xmalloc(bufsiz * sizeof(wchar_t));
 136
 137         do {
 138                 if (*argv) {
 139                         if ((fp = fopen(*argv, "r")) == NULL) {
 140                                 warn(_("cannot open %s"), *argv );
 141                                 rval = EXIT_FAILURE;
 142                                 ++argv;
 143                                 continue;
 144                         }
 145                         filename = *argv++;
 146                 }
 147
 148                 while (fgetws(buf, bufsiz, fp)) {
 149                         len = wcslen(buf);
 150
 151                         /* This is my hack from setpwnam.c -janl */
 152                         while (buf[len-1] != '\n' && !feof(fp)) {
 153                                 /* Extend input buffer if it failed getting the whole line */
 154                                 /* So now we double the buffer size */
 155                                 bufsiz *= 2;
 156
 157                                 buf = xrealloc(buf, bufsiz * sizeof(wchar_t));
 158
 159                                 /* And fill the rest of the buffer */
 160                                 if (!fgetws(&buf[len], bufsiz/2, fp))
 161                                         break;
 162
 163                                 len = wcslen(buf);
 164                         }
 165                         if (buf[len - 1] == '\n')
 166                                 buf[len--] = '\0';
 167                         reverse_str(buf, len);
 168                         fputws(buf, stdout);
 169                 }
 170                 if (ferror(fp)) {
 171                         warn("%s", filename);
 172                         rval = EXIT_FAILURE;
 173                 }
 174                 fclose(fp);
 175         } while(*argv);
 176
 177         free(buf);
 178         return rval;
 179 }
 180